Week 01: The London Fog Questions
Mortality Trends:
Referring to table 1 and figure 1:
1. Using the data in Table 1, construct a graph to compare mortality trends in the London Administrative County (LAC), the Outer Ring (OR) (see Figure 1), and the 160 Great Towns (not including London).
2. What information does the graph provide?
The graph shows the number of deaths attributable to the London Fog in various regions of England during the time period described. The graph also shows fluctuations in data, particularly spikes in cases and leveling-off periods.
Continued Investigation:
Referring to table 2 and figure 2:
3. In this situation, registered deaths (routinely collected) were used, saving time and money, and providing a rapid (“quick and dirty”) assessment of the situation. But, as usual, for speed, one pays a penalty. What are the limitations of death data?
4. Summarize what you know so far.
5. At this point, you have only been working with total numbers of deaths. What additional information should you have regarding the deaths?
Referring to table 3 and table 4:
6. What age groups were at greatest risk? (It would be helpful to visualize these data graphically if time allows).
Referring to table 5:
7. Table 5 presents the cause-specific mortality data. What specific diseases/conditions are responsible for the increase in mortality?
8. At this point, the assumption in the press and among the general public is that the excess deaths are in some way related to the fog, but, you do not know this to be true, therefore you should consider all possibilities. Speculate on the other possible causes for this excess mortality.
9. Considering the general assumption that the fog is related (and further suggested by the increase in respiratory deaths), how would you attempt to validate this assumption? What data do you need? Where might you obtain the data?
Mortality and Meteorological Data:
10. Table 6 presents mortality data along with meteorological data for 1–15 December 1952. Construct a graphic presentation of these data to determine if there is an association.
11. Is the increase in mortality in London related to variations in temperature, atmospheric pollution (smoke) or sulfur dioxide (S02) content?
12. What sources of routinely collected data might be useful to assess morbidity during the fog period?
Other Morbidity
13. In the present situation, data were available for applications and admissions to hospitals through the Emergency Bed Service Bureau. Table 7 presents these data. Do the data in Table 7 support the hypothesis of an air pollution effect?
14. In addition, morbidity information was available from the Ministry of Pensions and National Insurance. Table 8 summarizes these data. Do the data in Table 8 support the hypothesis of an air pollution effect?
15. Is the fog responsible for the increased mortality and morbidity?
16. What remedial measures would you suggest to prevent another “fog disease” episode due to S02 and smoke in the future?
